"The scale of these discrepancies is staggering, totalling billions of dollars. The problems with the official data do not provide evidence of corruption but they do raise profound questions about the quality of Angola's official figures on oil revenues," said Diarmid O'Sullivan of Global Witness.

"Angola's people are entitled to full and reliable information about the country's earnings from oil, which are vital to Angola's development. The figures published by the government fall short of this standard and need to be greatly improved," said Elias Isaac, Country Director of OSISA-Angola.

Angola relies heavily on oil revenues: nearly two-thirds of its government income and 42.5 per cent of its Gross Domestic Product currently comes from oil. Since 2004, the government has responded to concerns about corruption in its management of oil revenues by publishing detailed figures on oil production, exports, prices and taxes.

But the report uncovers serious gaps and anomalies in the figures for 2008 from the three most important sources of oil data: the Ministries of Finance and Petroleum and the powerful state oil company, Sonangol. Major findings include:

A gap, worth a notional US$8.55 billion, between the ministries' figures for volumes of oil sold by Sonangol in 2008. The gap between their figures for income taxes from oil companies has a notional value of over US$1.2 billion.

A gap of 87 million barrels between the two ministries' figures for oil exports in 2008. The lack of a visible explanation for this gap is deeply troubling.

In 2006, media reports said oil companies offered over US$3.2 billion in signature bonuses to Angola. But government accounts only seem to record US$998 million in receipts. They do not seem to record large dividends from Sonangol.

None of the official figures appear to be independently checked. Sonangol's accounts are independently audited but several caveats were raised by the auditors. So Angola's citizens have no assurance that the figures are accurate.

Angola's efforts at transparency fall short of international benchmarks such as the Extractive Industries Transparency Initiative (EITI). The report calls on the Angolan government to stage an independent review of the report's findings and to publish more comprehensive oil data which is independently verified by a third party. Global Witness and OSISA Angola urge the government to respond publicly to the report.

/Ends

Notes to editors:

The report examines annual oil sector reports from Angola’s Ministry of Petroleum, month-by-month data on oil exports and revenues from the Ministry of Finance, Sonangol's financial statements and other official reports where relevant.

All the data used for compiling the report is from 2008, the most recent year for which all existing sources were available at the time the report was completed in late 2010.